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tected a short, clear, and modest statement, entitled “ Remarks on 
Boulders, by Peter Dobson,” which, though little more than one 
page in length, contains the essence of the modified glacial theory 
at. which we have arrived after so much debate. First deseribing 
in a few lines the manner in which large boulders, weighing from 
ten cwt. to fifteen tons, were dug out in clay and gravel, when 
making the foundations for his own cotton factory at Vernon, and 
seeing that it was not uncommon to find them worn, abraded, and 
scratched on the lower side, “as if done (to use his own expression ) 
by their having | been dragged over rocks and gravelly earth im one 
steady position,” he adds this most remarkable sentence:—“ J think 
we cannot account for these appearances, unless we call in the aid of 
ice as well as water, and that they have been worn by being suspended 
and carried in ice over rocks and earth under water.’ To show 
also that he had read much and thought deeply on this subject, 
Mr. Dobson quotes British authorities to prove, that as ice-floes 
constantly carry huge masses of stone, and deposit them at great 
distances from their original situation, so may they explain the trans- 
portation of foreign boulders to our continents. 
Apologising therefore for having detained you long, and for 
having previously too much extended a similar mode of reasoning, 
I take leave of the glacial theory in congratulating American science 
in haying possessed the original author of the best glacial theory, 
though his name had escaped notice ; and in recommending to you 
the terse argument of Peter Dobson, a previous acquaintance with 
which might have saved volumes of disputation on both sides of 
the Atlantic. 
In the mean time, however we may attempt to account for the 
transport of boulders, the striation and polish of rocks, and the ae- 
cumulation of superficial detritus, we cannot quit the glacial subject 
without avowing our obligations to Venetz, Charpentier, and Agassiz, 
and above all to the last, for having brought the agency of ice more 
directly into consideration as a vera causa, to explain many pheeno- 
mena on the surface. Even we who differ from Agassiz in his ge- 
neralizations, and have not examined the Alps since the theory was 
propounded, should not hastily adopt opinions which may be modi- 
fied after a study of the glaciers in situ. “ Come and see” is the bold 
challenge of the Professor of Neuchatel to all who oppose him, and 
sanguine as to the correctness of his opinions, he is certain that many 
will be converted if they would but observe the phenomena on which 
his views are based. Truly we must acknowledge, that he was the first . 
person who roused our attention to the effects produced by the bottom 
of an advancing glacier, and if geologists should eventually be led 
to believe, that certain parallel scratches and striz on the rocks were 
in some instances due to glaciers moving overland, but in many 
other cases were produced by icebergs, we must remember that the 
fertile mind of Agassiz has afforded us the chief means of experi- 
mentally solving the problem. 
In conclusion, Gentlemen, it is gratifying to reflect, that not- 
withstanding the vibrations of opinion which have been caused by 
